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<h1 class="title">renderarea.cpp 示例文件</h1>
<span class="subtitle">painting/basicdrawing/renderarea.cpp</span>
<!-- $$$painting/basicdrawing/renderarea.cpp-description -->
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<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
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  ** $QT_END_LICENSE$
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  ****************************************************************************/</span>

  <span class="preprocessor">#include &quot;renderarea.h&quot;</span>

  <span class="preprocessor">#include &lt;QPainter&gt;</span>

  RenderArea<span class="operator">::</span>RenderArea(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)
  {
      shape <span class="operator">=</span> Polygon;
      antialiased <span class="operator">=</span> <span class="keyword">false</span>;
      transformed <span class="operator">=</span> <span class="keyword">false</span>;
      pixmap<span class="operator">.</span>load(<span class="string">&quot;:/images/qt-logo.png&quot;</span>);

      setBackgroundRole(<span class="type"><a href="../qtgui/qpalette.html">QPalette</a></span><span class="operator">::</span>Base);
      setAutoFillBackground(<span class="keyword">true</span>);
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> RenderArea<span class="operator">::</span>minimumSizeHint() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> <span class="type"><a href="../qtcore/qsize.html">QSize</a></span>(<span class="number">100</span><span class="operator">,</span> <span class="number">100</span>);
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> RenderArea<span class="operator">::</span>sizeHint() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> <span class="type"><a href="../qtcore/qsize.html">QSize</a></span>(<span class="number">400</span><span class="operator">,</span> <span class="number">200</span>);
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>setShape(Shape shape)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>shape <span class="operator">=</span> shape;
      update();
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>setPen(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qpen.html">QPen</a></span> <span class="operator">&amp;</span>pen)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>pen <span class="operator">=</span> pen;
      update();
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>setBrush(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qbrush.html">QBrush</a></span> <span class="operator">&amp;</span>brush)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>brush <span class="operator">=</span> brush;
      update();
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>setAntialiased(bool antialiased)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>antialiased <span class="operator">=</span> antialiased;
      update();
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>setTransformed(bool transformed)
  {
      <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>transformed <span class="operator">=</span> transformed;
      update();
  }

  <span class="type">void</span> RenderArea<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span> <span class="comment">/* event */</span>)
  {
      <span class="keyword">static</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span> points<span class="operator">[</span><span class="number">4</span><span class="operator">]</span> <span class="operator">=</span> {
          <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">10</span><span class="operator">,</span> <span class="number">80</span>)<span class="operator">,</span>
          <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">20</span><span class="operator">,</span> <span class="number">10</span>)<span class="operator">,</span>
          <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">80</span><span class="operator">,</span> <span class="number">30</span>)<span class="operator">,</span>
          <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">90</span><span class="operator">,</span> <span class="number">70</span>)
      };

      <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect(<span class="number">10</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">80</span><span class="operator">,</span> <span class="number">60</span>);

      <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> path;
      path<span class="operator">.</span>moveTo(<span class="number">20</span><span class="operator">,</span> <span class="number">80</span>);
      path<span class="operator">.</span>lineTo(<span class="number">20</span><span class="operator">,</span> <span class="number">30</span>);
      path<span class="operator">.</span>cubicTo(<span class="number">80</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">50</span><span class="operator">,</span> <span class="number">50</span><span class="operator">,</span> <span class="number">80</span><span class="operator">,</span> <span class="number">80</span>);

      <span class="type">int</span> startAngle <span class="operator">=</span> <span class="number">20</span> <span class="operator">*</span> <span class="number">16</span>;
      <span class="type">int</span> arcLength <span class="operator">=</span> <span class="number">120</span> <span class="operator">*</span> <span class="number">16</span>;

      <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>);
      painter<span class="operator">.</span>setPen(pen);
      painter<span class="operator">.</span>setBrush(brush);
      <span class="keyword">if</span> (antialiased)
          painter<span class="operator">.</span>setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing<span class="operator">,</span> <span class="keyword">true</span>);

      <span class="keyword">for</span> (<span class="type">int</span> x <span class="operator">=</span> <span class="number">0</span>; x <span class="operator">&lt;</span> width(); x <span class="operator">+</span><span class="operator">=</span> <span class="number">100</span>) {
          <span class="keyword">for</span> (<span class="type">int</span> y <span class="operator">=</span> <span class="number">0</span>; y <span class="operator">&lt;</span> height(); y <span class="operator">+</span><span class="operator">=</span> <span class="number">100</span>) {
              painter<span class="operator">.</span>save();
              painter<span class="operator">.</span>translate(x<span class="operator">,</span> y);
              <span class="keyword">if</span> (transformed) {
                  painter<span class="operator">.</span>translate(<span class="number">50</span><span class="operator">,</span> <span class="number">50</span>);
                  painter<span class="operator">.</span>rotate(<span class="number">60.0</span>);
                  painter<span class="operator">.</span>scale(<span class="number">0.6</span><span class="operator">,</span> <span class="number">0.9</span>);
                  painter<span class="operator">.</span>translate(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>);
              }

              <span class="keyword">switch</span> (shape) {
              <span class="keyword">case</span> Line:
                  painter<span class="operator">.</span>drawLine(rect<span class="operator">.</span>bottomLeft()<span class="operator">,</span> rect<span class="operator">.</span>topRight());
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Points:
                  painter<span class="operator">.</span>drawPoints(points<span class="operator">,</span> <span class="number">4</span>);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Polyline:
                  painter<span class="operator">.</span>drawPolyline(points<span class="operator">,</span> <span class="number">4</span>);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Polygon:
                  painter<span class="operator">.</span>drawPolygon(points<span class="operator">,</span> <span class="number">4</span>);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Rect:
                  painter<span class="operator">.</span>drawRect(rect);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> RoundedRect:
                  painter<span class="operator">.</span>drawRoundedRect(rect<span class="operator">,</span> <span class="number">25</span><span class="operator">,</span> <span class="number">25</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>RelativeSize);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Ellipse:
                  painter<span class="operator">.</span>drawEllipse(rect);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Arc:
                  painter<span class="operator">.</span>drawArc(rect<span class="operator">,</span> startAngle<span class="operator">,</span> arcLength);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Chord:
                  painter<span class="operator">.</span>drawChord(rect<span class="operator">,</span> startAngle<span class="operator">,</span> arcLength);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Pie:
                  painter<span class="operator">.</span>drawPie(rect<span class="operator">,</span> startAngle<span class="operator">,</span> arcLength);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Path:
                  painter<span class="operator">.</span>drawPath(path);
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Text:
                  painter<span class="operator">.</span>drawText(rect<span class="operator">,</span>
                                   <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>AlignCenter<span class="operator">,</span>
                                   tr(<span class="string">&quot;Qt by\nThe Qt Company&quot;</span>));
                  <span class="keyword">break</span>;
              <span class="keyword">case</span> Pixmap:
                  painter<span class="operator">.</span>drawPixmap(<span class="number">10</span><span class="operator">,</span> <span class="number">10</span><span class="operator">,</span> pixmap);
              }
              painter<span class="operator">.</span>restore();
          }
      }

      painter<span class="operator">.</span>setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing<span class="operator">,</span> <span class="keyword">false</span>);
      painter<span class="operator">.</span>setPen(palette()<span class="operator">.</span>dark()<span class="operator">.</span>color());
      painter<span class="operator">.</span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoBrush);
      painter<span class="operator">.</span>drawRect(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> width() <span class="operator">-</span> <span class="number">1</span><span class="operator">,</span> height() <span class="operator">-</span> <span class="number">1</span>));
  }

</pre>
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<!-- @@@painting/basicdrawing/renderarea.cpp -->
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